In the 19th century, gradualist assumptions were behind the thinking of most catastrophists as well as uniformitarians--and, in another field of study, even the Darwinians. To them, life--and earth--consists mostly of a series of small sometimes imperceptible moves over many millions of years. At first glance, to gradualists, evolution, not revolution, seems to have been, and to be, the norm.

Those gradualist assumptions continue into the 20th century, with certain exceptions for those in the natural scienes who believe in what they call 'punctuated equilibrium'--gradualism as usual interrupted by presumably unusual catastrophes.

A traditional gradualist assumption shared with uniformitarians has been that natural laws are immutable: now equals then and then equals now. The past and the present (and presumably the future) are as one.

But note: you can't logically believe in no fundamental change and some fundamental change (whether evolutionary or revolutionary) at the same time.

One gradualist assumption is that global catastrophes are not only rare but irregular and inconsistent. They are assumed to have no underlying pattern of recurrence and no consistent mechanism to create that recurrence. A possible exception would be certain extraterrestial mechanisms such as comets which appear, strangely enough, to be psychologically easier to accept than earth-bound mechanisms of global catastrophe.

Note: If terrestrial mechanisms can't be conceived of as revolutionary in nature, must global catastrophes that have occured always be assumed to have been totally random or can they be thought of as in some sense evolutionary--or some combination of the two?

Gradualist thinking, of course, is re-enforced by the results of radiometric dating methods which, by creating millions-of-years time-lines, tilt the mind away from thoughts of suddenness towards the infinitesimally slow. One could argue, of course, that's what objective evidence shows must be done.


To most people, the theory of plate tectonics is the prime example of gradualist thinking in current geology.

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